Pioneer VSX-LX70 Service Manual page 32

1
A
G
A IC401 (Pin 14) Buffer
No
Is the voltage
3.3V?
Yes
H
L531 (TP055) 1st Block 1.2V
No
Is the voltage
1.2V?
B
Yes
I
IC101 (Pin A12, etc.) 1st DSP 1.2V
No
Is the voltage
1.2V?
Yes
J
IC201 (Pin 3, etc.)
2nd DSP 3.3V
C
No
Is the voltage
3.3V?
Yes
t
OSC Inverter
IC751 (Pin 8)
No
Is the voltage
3.3V?
D Yes
K
2nd Block 1.25V
IC521 (Pin 5)
No
Is the voltage
1.25V?
Yes
L
E
IC201 (Pin 8, etc.) 2nd DSP 1.25V
No
Is the voltage
1.25V?
Yes
To Step 3
F
32
1
2
Check the parts and patterns
in the path.
The output and GND may be short-
circuited. Check the path between
them.
Check the parts and patterns
in the path.
Check the parts and patterns
in the path.
Check the parts and patterns
in the path.
No
Is IC521
abnormally hot?
Replace IC521.
Yes
The output and GND may be short-
circuited. Check the path between
them.
Check the parts and patterns
in the path.
2
3
Step 3: Operation of the Master Clock
M
CN401 (Pin 23)
Is the logic
gate "L"?
Yes
Does the
crystal oscillate
at 20 MHz
?
Yes
o
R148
Is there
an operation-master
clock signal
(20 MHz)?
Yes
p
IC201 (Pin 45)
Is there
an operation-master
clock signal
(20 MHz)?
Yes
To Step 4
VSX-LX70
3
4
CLK_ON
No
Check the output from the
DIGITAL MOTHER Assy.
No
Replace IC752, Q751.
MCLK1
No
Check the path, or replace IC751.
MCLK2
No
Check the path, or replace IC751.
4